Thousands of fans welcomed the Los Angeles Chargers to their new headquarters in Costa Mesa on Sunday morning as the team opened training camp for the upcoming NFL season with a practice at the Jack R. Hammett Sports Complex.

The franchise, newly relocated from San Diego, caused quite a buzz as the largely jersey-clad crowd watched the players run through drills.

Bleachers built to offer seating for about 3,000 people were packed, and many more fans filled the standing-room space.

Onlookers roared as longtime quarterback Philip Rivers threw passes to his receivers and handed the ball to primary running back Melvin Gordon.

Apart from the on-field activity, interactive games let fans try their hand at things like throwing a football at small targets on a board. A wall with full-size pictures of players enabled fans to see how they measure up to pros like Chargers defensive end Joey Bosa, who is 6-foot-5 and 280 pounds.

Guests also could visit a variety of food trucks, a pro shop with team merchandise and the Charger Girls for photographs.

Rivers told reporters that the fan showing was better than he anticipated. He said he had once endured a day of training camp where “like 12 people” showed up.

Cornerback Jason Verrett and defensive end Melvin Ingram said the fans have been amazing since the team arrived in Costa Mesa.

Kyle Evans, 25, of Costa Mesa said he’s a longtime Chargers fan and that it’s great to have the team in town. He said he’s hoping for a Super Bowl victory parade in Costa Mesa in coming years.